TM-9-2350-311-10 M109 Operator's Manual for M109A2, M109A3, M109A4 and M109A5 Download
Page 380 of 775
TM 9-2350-311-10 2–20 OPERATION IN UNUSUAL ENVIRONMENT/WEATHER — CONTINUED 2-20.4 Operation in Extreme Cold — Continued b. Starting Coolant Heater NOTE After coolant heater starts, it will keep working as long as there is fuel, electric current, air, and a flow of engine coolant. Coolant heater will automatically stop if coolant temperature reaches 245° F. 1 Turn HI/LO switch (4) on heater control box (2) to HI. 2 Hold START/RUN/OFF switch (5) at START. 3 Press-to-test light (1) will illuminate, indicating coolant heater (6) is operating. Immediately move START/RUN/OFF switch (5) to RUN position without hesitating in the OFF position. 4 Set HI/LO switch (4) for desired rate of heat. If set at Hl, coolant heater (6) will automatically go to low heat when coolant temperature reaches 190° F. If coolant temperature falls below 120° F, heat control will return to high. LOW position is suitable when coolant heater must burn for an extended period of time. c. Stopping Coolant Heater Place START/RUN/OFF switch (5) in OFF position. Coolant heater (6) will go to purge cycle. Fuel will shut off and burning will stop, when remaining fuel in coolant heater is exhausted. Blower will run at low speed until coolant heater is cool and then coolant heater will completely shut down. d. Cold Weather Starting (Vehicles with Engine Model 7083-7396) NOTE Cold weather starting procedures are to be used at 30° F (–1° C) and below. FLAME HEATER control switch and STARTER control switch must be activated at the same time. 1 If using winterization kit, stop coolant heater (6) before trying to start engine. Remove tarpaulins and roll into smallest tube form. Secure tarpaulins with webbing assemblies. Install exhaust outlet plug (3). 2 Charge batteries (especially after 24 hours of winterization kit operation). 2-274